Often, Jose Maria Gallardo del Rey will check out YouTube and find some stranger performing one of his compositions.

“I never know them,” he said. “I never meet them, these people from Russia or India or China or Japan. They’re playing my music, and it makes me really happy.”

While many classical guitarists perform old pieces, Gallardo del Rey prides himself on creating his own work, like composers during the Renaissance and Baroque times.

“I really needed to have language to express myself, and I found that through composition,” he said.

He’ll be further expressing himself — performing his composition “Glosas”—during the San Luis Obispo Symphony’s Pops by the Sea concert on Sunday.

A native of Seville, Spain, Gallardo del Rey began playing guitar around age 6, after an uncle gave him a guitar as a gift. He vividly remembers his debut concert — at age 9.

“I really remember that concert like it was probably one of the most important things I did in my life,” he said, noting he still has photos from that day. “Because I began to recognize the art of performance.”

Trained first in flamenco guitar, he went on to study classical guitar. Eventually, he would become a popular guitarist among symphonies.

Guitars in orchestras can be traced to “Concierto de Aranjuez,” a piece composed by Joaquin Rodrigo in 1939.

“And now I can tell you that probably 75 or 80 percent of my performances are with a symphony orchestra,” Gallardo del Rey said. “I’m very specialized in this matter.”

Consequently, his compositions are often written with orchestras in mind.

“Beethoven said one time that the guitar is like a miniature orchestra,” he said. “Because of the different timbres and colors you can get from the instrument.”

It also helps that his wife, Anabel Garcia del Castillo, is a violinist who often performs with him.

“It’s the best way for me, as a composer, to write for a violin — having a violinist at home,” he said.

A frequent guest in San Luis Obispo, Gallardo del Rey first came here in 1986, after meeting Cal Poly music professor Craig Russell in Spain.

“He showed me the manuscript of his guitar concerto. I began to read it, and I began to play, and he really liked it — the way I did it,” Gallardo del Rey said. “So years later, he called me and said, ‘Do you remember what I told you in Seville

years ago? We’re making the concert for next season, and you are the soloist.’ ”

Since that time, he has performed here numerous times — and gone on to become a world-renowned classical guitarist.

Last year, he premiered “Glosas,” a double concerto for guitar and violin, in San Luis Obispo. Commissioned by the symphony, the piece is in four movements and evokes the sounds of Spain.

Last weekend, Gallardo del Rey and the symphony began recording the piece for an album expected to be released sometime before Christmas. At the Pops concert, Gallardo del Rey and Garcia del Castillo will perform a portion of “Glosas” with the symphony. (The symphony will also perform romantic standards, including Gershwin’s “American in Paris.”)

While some classical guitarists perform many solo shows, Gallardo del Rey — who has performed with artists such as opera singer Placido Domingo and rock star Elton John — sees the classical guitar as an ambassador of sorts.

“The guitar has a lot of potential because it’s an instrument that shares the best of many traditions —of classical, of popular, of flamenco, baroque, pop. So it’s like a big family pulled together in one instrument.”

Reach Patrick S. Pemberton at 781-7903.